From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7FE7C433DB for ; Mon, 8 Feb 2021 20:17:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64CD164DBD for ; Mon, 8 Feb 2021 20:17:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233438AbhBHURU (ORCPT ); Mon, 8 Feb 2021 15:17:20 -0500 Received: from mga11.intel.com ([192.55.52.93]:19742 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235781AbhBHSvA (ORCPT ); Mon, 8 Feb 2021 13:51:00 -0500 IronPort-SDR: jtO57MKjPDT2Hi85PUtM1GHO3bFumY+0XQqEcMQmoqatUfBm/XjK/o76hIlLmzIye30poOffZq IyRhZY/ccS1A== X-IronPort-AV: E=McAfee;i="6000,8403,9889"; a="178251561" X-IronPort-AV: E=Sophos;i="5.81,163,1610438400"; d="scan'208";a="178251561" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2021 10:50:11 -0800 IronPort-SDR: RKBHoDdAWK2blnUYN00Qk4/M1GPezTS0E9lZ/If3NWriwtfE4VnzSdkvSBoLQzNvY2P1WCjvA+ SuIcuc84nSYQ== X-IronPort-AV: E=Sophos;i="5.81,163,1610438400"; d="scan'208";a="487522995" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.251.11.33]) ([10.251.11.33]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2021 10:50:08 -0800 Subject: Re: [PATCH v19 06/25] x86/cet: Add control-protection fault handler To: Borislav Petkov Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Michael Kerrisk References: <20210203225547.32221-1-yu-cheng.yu@intel.com> <20210203225547.32221-7-yu-cheng.yu@intel.com> <20210205135927.GH17488@zn.tnic> <2d829cba-784e-635a-e0c5-a7b334fa9b40@intel.com> <20210208182009.GE18227@zn.tnic> From: "Yu, Yu-cheng" Message-ID: <690bc3b9-2890-e68d-5e4b-cda5c21b496b@intel.com> Date: Mon, 8 Feb 2021 10:50:07 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210208182009.GE18227@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/8/2021 10:20 AM, Borislav Petkov wrote: > On Fri, Feb 05, 2021 at 10:00:21AM -0800, Yu, Yu-cheng wrote: >> The ratelimit here is only for #CP, and its rate is not counted together >> with other types of faults. If a task gets here, it will exit. The only >> condition the ratelimit will trigger is when multiple tasks hit #CP at once, >> which is unlikely. Are you suggesting that we do not need the ratelimit >> here? > > I'm trying to first find out why is it there. > > Is this something you've hit during testing and thought, oh well, this > needs a ratelimit or was it added just because? > I have not run into the situation. Initially it was there because other faults have it. When you asked, I went through it and put out my reasoning. I think it still makes sense to keep it. -- Yu-cheng